tapir/applications/application_chain.go

63 lines
2.1 KiB
Go

package applications
import (
"git.openprivacy.ca/cwtch.im/tapir"
)
// ApplicationChain is a meta-app that can be used to build complex applications from other applications
type ApplicationChain struct {
TranscriptApp
apps []tapir.Application
endapp tapir.InteractiveApplication
capabilities []tapir.Capability
}
// ChainApplication adds a new application to the chain. Returns a pointer to app so this call
// can itself be chained.
func (appchain *ApplicationChain) ChainApplication(app tapir.Application, capability tapir.Capability) *ApplicationChain {
appchain.apps = append(appchain.apps, app.NewInstance())
appchain.capabilities = append(appchain.capabilities, capability)
return appchain
}
// ChainInteractiveApplication adds an interactive application to the chain. There can only be 1 interactive application.
func (appchain *ApplicationChain) ChainInteractiveApplication(app tapir.InteractiveApplication) *ApplicationChain {
appchain.endapp = app
return appchain
}
// NewInstance should always return a new instantiation of the application.
func (appchain *ApplicationChain) NewInstance() tapir.Application {
applicationChain := new(ApplicationChain)
for _, app := range appchain.apps {
applicationChain.apps = append(applicationChain.apps, app.NewInstance())
}
applicationChain.capabilities = appchain.capabilities
return applicationChain
}
// Init is run when the connection is first started.
func (appchain *ApplicationChain) Init(connection tapir.Connection) {
appchain.TranscriptApp.Init(connection)
for i, app := range appchain.apps {
// propagate the transcript to the app
app.PropagateTranscript(appchain.transcript)
// apply the app to the connection
connection.SetApp(app)
// initialize the application given the connection
app.Init(connection)
// if we hit our guard then carry on, otherwise close...
if !connection.HasCapability(appchain.capabilities[i]) {
connection.Close()
return
}
}
}
// Listen calls listen on the Interactive application
func (appchain *ApplicationChain) Listen() {
if appchain.endapp != nil {
appchain.endapp.Listen()
}
}